Haloalkanes Flashcards
What is heterolytic fission
What is homolytic fission
What is a reaction mechanism
Is a series of steps that show what happens in a chemical reaction.
Shows the movement of a pair of electrons
The different types of mechanisms
Free Radical Substitution
Nucleophilic Substitution
Electrophilic Addition
Elimination
What is a free radical
A species with an unpaired electrons
What is substitution
A reaction where an atom/group replaces another atom/group
Steps to free rad sub
- Initiation
- Propagation
- Termination
How does an initiation reaction start?
When UV light breaks down Cl2 to form chlorine free radicals
The C-H requires more energy to break than the Cl-Cl
Equation for initiation
Explain the propagation step
Explain termination step
What is a nucleophile
Lone pair electron donors
This is because the halogen atom is more electronegative than carbon atoms and so the C of the C-H bone is delta positive
How is the rate of reaction affected by the strength of the halogen bond?
What are the different reagents in nucleophilic substitution
NaOH
KCN
NH3
Conditions for NaOH
Aqueous, warm
Mechanism for NaOH
What is the condition for KCN
Ethanolic, warm
Mechanism for KCN
Conditions for NH3
Excess concentrated ammonia dissolved in ethanol pressure in a sealed container
Mechanism for NH3
Reagent used in elimination reaction
KOH
What does the OH act as in elimination.
Base
What does OH act as in a substitution reaction
Nucleophile
Conditions for KOH or NaOH in elimination
Ethanolic, hot
Mechanism for elimination reaction
Ozone formation
What is the ozone
A layer that protects the earths surface from the harmful effects of UV radiation
Ozone depletion
UV and CFCs
Ozone and chlorine
What is electronegativity
The power of an atom to attract the two electrons in a covalent bond
What is an electrophile
Lone pair electron acceptors
This is because the C=C double bond is very electron rich die to the electron cloud of the pi bond
What is an addition reaction
The C=C double bond opens up and an atom or group of atoms joins onto each C of the C=C double bond
During the mechanism, a carbocation is formed. Where more than one carbocation can be formed, the main product will be formed from the more stable carbocation.
The different reagents with electrophilic addition
Br2
HBr
H2SO4
H2O
Conditions for Br2
Aqueous
Reaction mechanism for Br2
Conditions for HBr
no conditions
Reaction mechanism for HBr in electrophilic addition
Conditions for H2SO4 in electrophilic addition
Cold, concentrated H2SO4
Reaction mechanism for electrophilic addition H2SO4
Conditions for H2O in electrophilic addition
Acidic conditions
Reaction mechanism with H2O in electrophilic Addition
